Field of the Invention
The present invention relates to image display devices based on observer motion parallax.
Description of the Related Art
JP Patent No. 3973907 discloses an image data creating device and an image display device. These devices capture images of many parts, of an object to be imaged, including an inner surface, an outer surface, and positions before and after displacement, and store data of the images. An observer can select an image of a desired part of the object by operating a processing unit, to display the image on a display unit. However, with the image data creating device and the image display device, it is impossible to view a three-dimensional (3D) image based on observer motion parallax.
As a 3D image display device, a device using the binocular parallax of an observer is known. The device causes the right and left eyes of the observer to view image information different from each other. This operation allows the eyes of the observer to perceive the image as a 3D image. With the display device, the observer needs to wear special glasses. This is often pain for the observer.
Meanwhile, JP2014-534656 discloses an image display device using observer motion parallax, not binocular parallax. The image display device receives a plurality of two-dimensional (2D) images of a scene that is an object to be observed. 3D information associated with the scene is determined by using these 2D images, and a user viewing angle with respect to a display is determined. Next, in the image display device, the 3D information and the user viewing angle are used to present a generated image on the display. If the user moves with respect to the display, a correspondingly new user viewing angle is determined. The 3D information and the new user viewing angle are used to display a different generated image. The image display device is, so to say, a device that provides sequential three-dimensional perception. Here, such an image display device is also referred to as 3D image display device.
However, regarding the image display device disclosed in JP2014-534656, a relationship between a user viewing angle and a visual angle is not clear. That is, a specific method for determining a source image having a visual angle corresponding to a user viewing angle is not disclosed.